Megan Fox and Machine Gun Kelly have an interesting, whirlwind romance to say the least. Now, the singer revealed the story behind the piece of jewelry that he has from his girlfriend that is a bit out of the ordinary.A post shared by the Blonde Don (@machinegunkelly)On an appearance on the ‘Ellen DeGeneres’ show Wednesday, the 31-year-old explained the story behind the drop of Fox’s blood he has in a necklace that he wears.